In your search of adapters, you probably found two types:
- Those with lenses
- Those without lenses
Those without simply act as spacers, bringing the flange focal distance up to that of the design for the lens. For example, the Sony A7RII has a FFD of 18mm while the Nikon F mount has an FFD of 46.5mm.
This means that any Sony-> Nikon mount need simply space the lens 46.5mm from the sensor in order to "fit" it to the camera.
If working the other way around, you can see the obvious problem: Sony mount lenses are meant to be closer to the sensor than you can physically add them on a Nikon. This is similar to using an extension tube with a normal F-mount lens - namely, focus can be achieved at certain distances but focusing to infinity is impossible.
In order to compensate for this, the adapters may use additional lenses to further tweak the light making it's way to the sensor. While they will account for the focal distances, they are generally of sub-optimal quality and rob you of image quality such that the general recommendation is: if using a lensless adapter: go for it. If using an adapter with a lens: forget-about-it...the loss in image quality is simply not worth it.